Field of the Invention
The present disclosure relates to an ink, an ink stored container, an image forming method, a liquid discharging apparatus, and an image.
Description of the Related Art
Inkjet printing methods have been spreading rapidly recently, for the reasons that inkjet printing methods enable easy printing of color images and running costs of inkjet printing methods are low. As inks, water-based dye inks obtained by dissolving dyes in aqueous media and solvent inks obtained by dissolving oil-soluble dyes in organic solvents are used. From environmental and safety viewpoints, inks obtained by dissolving water-soluble dyes in water or in water and water-soluble organic solvents are used in offices and households. However, there is a problem that images formed with inks containing such water-soluble dyes are poor in water resistance and light resistance.
In this regard, water-based pigment inks obtained by dispersing particulate pigments in water are paid attention. Inks containing water-dispersible pigments are known to be excellent in water resistance and light resistance. However, when pigment inks are printed on gloss paper, the pigments, which are coloring materials, do not permeate internal portions of ink receiving layers, but remain on surfaces of the gloss paper and form coating films. This makes scratch resistance of printed surfaces poorer than when pigment inks are printed on plain paper or when dye inks that permeate internal portions of ink receiving layers are printed, leading to a problem that when printed surfaces are scratched after printing, printed coating films may peel or scratched matters may cause stains.
For the problems of scratch resistance, for example, there is proposed a method of combining a resin-coated pigment and a polyurethane resin (see, e.g., Japanese Unexamined Patent Application Publication No. 2013-155322). There is also proposed addition of a wax as a lubricant in an ink in order to provide the ink with a function of reducing a coefficient of friction of a printed image surface (see, e.g., Japanese Unexamined Patent Application Publication No. 2010-155359).
However, such inks excellent in scratch resistance have problems of discharging reliability degradation due to local drying at nozzle portions of inkjet printer heads and maintenance property degradation due to thickening and coagulation caused when water evaporates from waste inks.
Hence, there is proposed a method of adding an amine neutralizing resin in order to improve durability of an image coating film and also adding a glycol ether or an alkane diol in order to simultaneously ensure discharging reliability (see, e.g., Japanese Unexamined Patent Application Publication No. 2011-74336).
There is also proposed a method of using in combination, an organic amine salt water-soluble organic resin and a divalent alcohol-based solvent free of ether linkage in order to satisfy both of a drying property after printing and scratch resistance (see, e.g., Japanese Unexamined Patent Application Publication No. 2008-19287).